The invention relates to a method for producing an electrode stack for a battery cell by means of cutting ribbon-shaped elements to form plate-shaped segments and stacks of segments. The invention also relates to a battery cell that comprises an electrode stack that is produced according to the method in accordance with the invention.
Electrical energy can be stored using batteries. Batteries convert chemical reaction energy into electrical energy. A distinction is made between primary batteries and secondary batteries. Primary batteries are only capable of functioning once whereas secondary batteries that are also referred to as rechargeable batteries can be re-charged. A rechargeable battery uses in particular so-called lithium ion battery cells. These are characterized inter alia by high energy densities, thermal stability and an extremely low self-discharge rate.
Lithium ion batteries comprise a positive electrode that is also referred to as a cathode, and a negative electrode that is also referred to as an anode. The cathode and also the anode each comprise a current collector and a layer of active material is applied to said current collector. The electrodes of the battery cell are configured in a sheet-like manner, said sheets being separated by an intermediate layer of a separator that separates the anode from the cathode, and said sheets being joined together to form an electrode unit.
Such an electrode unit is configured by way of example as an electrode stack in which multiple plate-shaped layers of anode, cathode and separator are layered one above the other. An electrode unit may also be configured as an electrode winding, wherein the anode, the cathode and the separator are in the form of ribbon-shaped strips and are wound to form the electrode winding.
The two electrodes of the electrode unit are connected in an electrical manner to the poles of the battery cell that are also described as the terminals. The electrodes and the separator are encompassed by an electrolyte that is generally in a fluid form. Moreover, the battery cell comprises a cell housing that is manufactured by way of example from aluminum. The cell housing is generally designed in a prismatic shape, in particular a cuboid shape, and is pressure-resistant. However, other shapes of housing are also known, by way of example circular-cylindrical housings or also flexile pouch cells.
The document US 2010/0075215 A1 discloses a battery and a method for producing a battery. First of all, an anode material is applied to a first separator paper and a cathode material is applied to a second separator paper. An anodic collector material is subsequently applied to the anode material, and a cathodic collector material is applied to the cathode material. The two separator papers that are coated in this manner and also a third separator paper are connected to one another and cut to form electrode segments.
The document US 2014/0099538 A1 discloses a solid body battery having a lithium metal anode and a cathode that comprises a sheet-like current collector. A cathodic active material is applied as a slurry to the current collector. The anode, the cathode and a separator are joined together and cut once the cathodic active material has dried.